i guess if it isn't for gaming that wouldn't matter.
the thing with PCs is once you build of have one you already have things like a power supply, a hard drive, a case, an optical drive. you don't have to rebuy those things so all you end up needing is a new mobo/processor/video card.
i paid about $850 at Microcenter and walked out with a new case, 16 GBs of RAM, a GTX 670, a 3570K core i5, a better than stock air cooler, a new power supply, and that MSI mobo.
i already had an OS, several hard drives, and an optical drive at home. in all honesty i had a case and cooler too but i ended up keeping those and moving my old build into my bedroom.
my pc runs at 4.2 GHz on air cooling all the time. you probably can't even overclock a store bought PC.
